Q&A: The Incredible Birth of Octuplets

The birth of octuplets at a California hospital yesterday is a gestational feat that has happened only one other time in the United States, doctors said.

The event required a team of 46 to carry out the Caesarean section at Kaiser Permanente Medical Center in Bellflower. As of this writing, Mom and all eight babies — six boys and two girls — were said to be doing fine, despite being 9 weeks premature.

"It would be very unlikely that this would be natural," said James Airoldi, maternal fetal medicine specialist and director of Obstetrics at St. Luke's Hospital and Health Network in Bethlehem, Pa. "It's very likely this was the result of some form of ovarian stimulation with the use of fertility drugs." This method would cause the ovaries to produce more follicles (each of which releases an egg) than normal.

"In vitro fertilization won't get you this [octuplets], because most doctors who do in vitro fertilization will only put two or three embryos back," Airoldi said, adding that even if a doctor inserted three embryos back into a woman's uterus and one of these split to produce twins, you'd only get four embryos.

"There's no doctor who would've put seven or eight embryos back in. That would be totally irresponsible of any doctor," he said.

The likely cause: so-called ovarian stimulation and fertility drugs, which cause a woman to produce more eggs than normal.

Do multiple babies share the same placenta?

Only identical twins, which would come from the same egg that splits, could share the same placenta, a pancake-shaped organ that attaches to the inside of the uterus and is connected to the fetus by the umbilical cord. The placenta delivers nutrients and oxygen from the mother's blood to the fetal blood, while transferring the baby's waste in the other direction.

The other babies, which come from separate eggs, would each pull nutrients from a separate placenta.

"They can't because their bellies are so big. So usually it amounts to trying to eat small frequent meals and trying to keep your calories up to at least 3,000 calories per day," he added.

Does carrying octuplets put more stress on a woman's body?

A resounding yes. "These babies are the most efficient parasites in the world," Airoldi told LiveScience. "They are taking every ounce of iron to build their red blood cells and every ounce of calcium to build their bones. So if mom isn't supplemented, mom is going to end up with nothing in the bank."

Have multiple births increased in the United States?

"Absolutely," Airoldi said. "I'll see 25 patients a day and at least five of them will be multiple gestation."

Over the past two decades, multiple births in the United States have skyrocketed, with the number of twins born between 1980 and 2003 increasing by more than 65 percent and the number of higher-order multiples (triplets or more) jumping four-fold during that time, according to the National Center for Health Statistics. Today, more than 3 percent of all babies born in the United States are multiples, with most being twins.

Why? The fact that more women are getting pregnant at older ages and the use of fertility drugs and other artificial fertility methods, according to Airoldi.

For older women, "their ovaries are trying to get that one last party in, that one last shot at conceiving so they have this overshoot phenomenon where they may release two eggs at once, trying really hard to desperately conceive before they go kaput," Airoldi said.

"Older women that conceive are at higher risk of multiples," he said. "And we are seeing women conceiving at later ages. And we also see higher rates in fertility medication used to conceive."

How many offspring do non-human animals have?

For domestic animals, dogs seem to take the medal for most babies. In 2005, a Neapolitan bull mastiff in England broke a world record when the mother dog gave birth to a litter of 24 puppies, according to media reports.

And on Dec. 23, 2008 a 3-year-old Dalmatian named Button living in the United Kingdom gave birth to 18 puppies by Caesarean section, according to British media reports. Last year, Button gave birth to a litter of 16 pups. Perhaps fittingly, the Dalmatian mother is the daughter of a dog that starred in the Disney film 102 Dalmatians.

The average number of puppies in a litter ranges from six to 10, according to the Humane Society of the United States. The average number of kittens in a litter is around four to six.

For wild animals, the tailless tenrec (Tenrec ecaudatus), a shrew-like mammal, can give birth to up to around 31 offspring, although the normal litter size ranges from 12 to 15, according to the University of Michigan Museum of Zoology. Females are able to suckle up to 24 young ones.

Other animals' litter sizes (live births), according to the University of Michigan Museum of Zoology:

Naked mole rat (Heterocephalus glaber): up to 27 with an average of 12

House mouse (Mus musculus): Litter can range from three to 12 offspring, which are born naked and blind.

Common rat (Rattus rattus): six to 12 with an average of eight

Black-tailed prairie dog (Cynomys ludovicianus): one to six with an average of three

Jeanna Bryner

Before becoming managing editor, Jeanna served as a reporter for Live Science and SPACE.com for about three years. Previously she was an assistant editor at Scholastic's Science World magazine. Jeanna has an English degree from Salisbury University, a Master's degree in biogeochemistry and environmental sciences from the University of Maryland, and a science journalism degree from New York University.